Wireless networks are finding increasing applications in our society giving rise to an explosive demand for wireless data. Smart phones, Wireless LANs (WiFi) and wireless sensor networks are some of the popular examples. To meet this ever increasing demand, the 4G standards are introducing a variety of spectrally efficient technologies such as the multiple antenna transmitters and receivers (MIMO), sophisticate interference management techniques, and additional base stations (called relay stations) to increase coverage and reliability. Fundamental information theoretic analysis of these networks and technologies and designing coding and decoding techniques to facilitate their practical implementation is the goal of our research group.
Current research themes:
Interference Communication Network:
In this area, we concentrate on finding the fundamental rate of information transfer from a set of transmitting nodes to a set of receiving nodes who operate in the same signal space and therefore interfere with each other’s signals. Recent research has revealed that much better performance can be realized if the different nodes are allowed to operate in the same signal space rather than separating them in frequency or time.
A relay channel refers to a configuration, where the signal transmitted by the set of source nodes is forwarded by one or more helping nodes towards the set of destination nodes and thereby can achieve a better reliability and rate. In recently defined 4G standards provision for two types of relays are incorporated: 1) a relay station that will enhance the performance of a end user; and 2) a relay which will extend the coverage of the base station beyond its cell limit.
Space Time Block Codes:
In communication channel with multiple transmit and receive antennas (MIMO) coding can take place across both the time and antenna dimensions as against to only the time dimension in classical single antenna communication links. Construction of STBCs for MIMO multi-user channels is another interesting area of our research.